Ammunition for open chamber guns



y 1961 D. DARDICK 2,983,223

AMMUNITION FOR OPEN CHAMBER GUNS Original Filed Sept. :5, 1954- mmvm. 04W0 OIQRDICK BYVW Jab;

ate t d. May 9 .1961.

United S at s ha emjfo i David Dardick, New York, N.Y., assignorl toDal-dick 1 Corporation, a corporation of Delaware Qriginal applicationSept. 3,1954, Ser. No. 454,045, now

7 "Patent N o.'2,865, 126, dated Dec. 23, 1958. Divided and applicationMay 5,1958, Ser. No. 733,162

16 Claims; (Cl. 3!8) This invention relates to ammunition foropen-chamber guns.

Serial No. 454,045, filed'Septernber 3, 1954, n'ow Patent g nte D e b r2 .5.8. or p n C emh t Cum e m ie Th re r-f" t le obje t o is nvent tipre i e e y n l improved ammunition for open chamber guns;

2 The open chambers of the drum are disposedin uniformly spaced relationto each other aroundjthe circum; ference of the drum. Thus, foreachrevolution of the drum, each chamber will travel once around therotation a1 axis of the drum in a closed circular path. path, startingfrom a loading position passes successively through a firing or batteryposition and an ejecting posi; tion, and thence to the loadingpositionagain, 'to com? plete the cycle. Each chambenwhile in transit throughthe loading position, is radially supplied automatically with a round ofammunition from a magazine unit which is preferably, detachablyconnected to, and, forms-a handle of, the gun.

This application is a division of co-pendingapplication I It is anotherobject of thisinvention toprovideama munition for an open chamber gun;which will be substan tially 'proofagainst rupture longitudinally of thecase d l an e m n a u e a. owe os en ;w h.- he

e ,e e s os y'ma e a si h n. hasher e re b en deemed feasible orpractical.

Other and ur her ie t dad an eges f; t i i e tion will appear fromthefollowing"description, the ace mpe y rewi sand; e app nd d a mst Inthe co-pending application Serial No. 4541 145 now 5 Patent No.2,865,126, there is disclosed an open rotary chamber gun wherein arotary drum of initially cylindrical contour is mounted for rotation onits cylinder axis in a st ong a d rigid rame. T e cyli der. Surface ofth um is.v rad al y. d presse v r: a. po ion o i a ea o provide one, andpreferably more than one, trough-like r ess or chamb r. pa al elto the rt onal; a s of; t

dr m. 1 Th recesses ar i eut ea in shape bein of un form non-circularcontour from end to end in parallel planes normal to the rotationallaxisofthe drum and tap ed n wid h in sa no l Pl es r a: maximum a thepp pormo .1 thei ha nberrto ii/minimum at. the baset ereoh E eh re e eonsttutee? n pen artr d eh mh h e h the. Qpeuton or mouth-oi whiehi heieor ene ng y shap uenfl re l r e e eeped vcartridge ett s n e ti n adap dt hen er iedredie v' ly of the drumandtobeseated the,chamber..--=-

The side. w lls f u h. op n chamber eenye ge nr u eu itudinallye fromtop to om d y hefla hut are; preter hly uniformly urv nnp r l el: planorma to the rotation l axis of the drumrto th sam ra ius asthecylindersurface of thedrum, I l I v, a 1 Ea h ehamh rruns from on to he other-ofnainef p a p anes n rmal o t e :ro ational a 's-o xthe drum f: curvatureand? marking, espe ively. the barrel ndiandi the pri e oil-he. ch mber.thr ughw eh he u let or. preieet el of r e. seat d wit inthe hamber, ayhed s har ed end of he-.chamh raT-he ro ary rum. i eonst eted andarranged to provide an escape opening at 'the barrel; end

into the r f. a arr l' t snail: lignmen the e-i;

with. Likewise, the rotary is constructed and an ranged to; provide anaccessjopeningat; the prime end of the chamber through which. a firi g-pn or ethe 1 t: ablefiring means may :be caused to act on the primer oftheeartri getofire hesame. 1, Y 2. In accordance with a.preferred}eenstrti neae ehaini hen runs from. end to end ot the drum, the acc ss andescape openings, of the chamberbeing locat ed inopposrt'e end; faces ofthe a'ndheiug of the same size and vshapeastherflmrrflserinerosssection:

. tpgthe druin axis, a breech surface disposed too the magazine unitbeing open at one end and being de signed to receive, at the oppositeend, a load of ammunition. The ammunition load is arranged in thestorage chamber in one or more rows of side-by-side rounds, the roundsbeing delivered successively through theopen end of the magazine-unit tosuccessive cartridge chambers of the rotary open chamberdrum as itrotates,

The open chamber rotary drum serves as'a rotary gating and conveyingdevice functioning in rotation to pick-ofi one round of ammunition at atime from the magazine unit and to convey the round'sequentially to thebattery position for firing and thence to the ejecting position forejection from the drum. & position, the empty cartridge caseisautomatically ejected from the chamber by suitable ejecting meansprojected into the chamber at a suitable phase of the cycle.

The drum is suitably disposed at the open end of the magazine unit tobring the open chambers of the drum successively into. opposition with aterminal round of ammunition in the opening, as the drum is rotated. .Tothis same end, means are provided at the opposite end of the magazineunit for yieldably urging the row or rows of ammunition in thestationary magazine chamber to-, ward and into contact with the cylindersurface of the rotary drum so that the terminal round of ammunition in agiven row will be caused to enter and be seated in the firstemptyopenchamber brought into opposition there: with.

- The'stationary frame of the, gun is constructed and ar ranged to serveas a breech for both the opentop or mouth and the primerv end of eachcartridge chamber,

whenthc chamber is in battery positiom, To thisend, the ameis eta confir te Prov edin ly of thedrum axis a breech surface of cylindricalcontt.nn v which is concentric'with thedrum and is suitably dimensioned; in directions normal to and longitudinally of the rotationalaxis of the drum, to span the open top or mouth 7 of, the; openchamber'from side-to-side and from end-to end, when the chamber is inbattery position. v

The arcuatebreech surface has a radius or curvature only slightlylargerthan that of the dmm so that the cylinder surfaces of the drum andbreech will .be insubstantiallywiping engagement wheninopposin'grelation to each other. flfhus, each open chamber onreachingits batt y pos tion wi e e y p d b the uel breech surfaceand'thus beconverted intoa closed car;

tridge chamber of generally triangular shape oifering a s b antia ei f nl y o i ou s pnert lgiwell su fa e a a which t e ee e ee m y PeI N Forthe purpose of closing the primer end of he. open ar r ehemh ba ter pesion t e remefe he i els ee e t d ad; r n edtepr yide n resins a d closey eaeed-l e a o he m n r I end f hed m se s he n s b tan f In h la tespan the recess from side-to-side and from top to bottom, thereby toprovide a surface against which the primer end of the cartridge mayexpand and press when fired.

Irigger actuated means are provided for effecting rotationjof the rotarydrum so' as to bring the successive recesses into battery position 'andfor firing the individual rounds when so positioned. i In accordancewith thisinvention, there is provided a cartridge for use with theopen-chamber guns aforesaid wherein the bullet or projectile of thecartridge, together 'with the propellant therefor, is wholly containedwithin the case or'shell of the cartridge. i Exteriorly, the. case is ofa contour circumferentially,

asto part of its circumference, matching that of the side walls of therecess or open chamber of the openohamber gun aforesaid in which it isto be seated. As to the remaining part, it is of cylindrical contourwith its radius of curvature matching th at of the cylinder surface of'the drum. Thus, when positioned in an open chamber of the gun, thecartridge. will fit snuglyagainst and-be supported bythe side walls ofthe chamber. Moreover, because of its cylindrical surface portion havinga radius of curvature matching that of the cylinder surface of the drum,it serves to provide, in effect,.a continuation of the cylinder surfaceof the drum over the entire span of the chamber at its mouth.Preferably, the case is of triangular shape, each of its sides beingarcuate and of equal radius of curvature so that when used in an openchamber whose sides are. correspondingly curved, it may be inserted inthe chamber with. any one of its three apices at the bottom of thechamber. I

lnteriorly, the case is of a contour circumferentially which also isother than circular so that the gas pressure created within the case onfiring will tend to cause the case to assume a circular shape incross-section and thus to be firmly supported externally throughout itsentire circumferential periphery by the side walls of the open chamberand by the arcuate breech surface of the gun frame. Advantageously, theinternal circumferential contour of the case may be geometricallysimilar to its external circumferential contour, since the fabricationof the case is facilitated in so doing, and the wall thicknesses of thecase may be closely controlled within permissible limits. In accordancewith the invention, moreover, the thickness of the case is preferablygreater at the intersections of the case walls than between theintersections. In this way, reinforcement is provided at the corners ofthe case so that the possibility of the case bursting longitudinallyalong the line ofeither joint between the rotary drum and cylindricalbreech surface of the gun, iscompletely, or substantially completely"eliminated.

" The casing case isof a length coextensive with that of the openchamber in which it is to be used. One of its ends, the primer end, isclosed by a primer unit'which, in battery position of the open chamber,isadapted on firing of the cartridge to, press against and beopposed bythe end "breech surface ofthe gun frame. H 1

Means are provided within the case for supporting the bullet of thecartridge wholly withinthe case in annularly spaced relationthereto, andfor forming a sealing flange at the other end, the muzzleend, of thecase. The sup} porting and flange-forming means as here preferablyem;

bodiedcomprises an imperforate sleeve, preferablyfof cylindricalcontour, disposed centrally andlongitudinally of the case in annularlyspaced relation thereto, the sleeve being hermetically sealed tolthecase at its outer end and forming an annularobturating flange thereat'.

The sleeve. telescopically receives, and securely but-re leasablyholds,the bullet in'coaxial alignment therewith,

positionto be propelled axially fromthebase intothe 4 here ofthe gunbarrel. The interior of the base, includ ing the annular space betweenthe sleeve and the case, contains the propellant. Advantageously, thesleev'e'inay be rifled internally, if desired, forco-action-with to witha cylindrical breech surface 11 which as shown iri axis of the bore 10of thebarrel.

tating band on the bullet. In such case, the rifting or pre-engraving ofthe sleeveor bulletshould conform in pattern to that of the rifling ofthe barrel of the gun with which the cartridge is to be used, it beingapparent that the cartridge must be properly indexed in its recess toachieve alignment of the rifling of cartridge and barrel. To this end,the cartridge and the open chamber of the gunin which it is to beemployed may be of a contour such that the cartridge may be received, orpre-indexed, in the chamber in only one position. [[t will be understoodthat since the annular space between the case and sleeve is closed atits outer end by a connecting annular obturating wall portion, theexpanding gases, in the cartridge on firing will tend to force theconnecting obturating wall intofirm sealing engagement with the breechend of the gun barrel, thus effectively preventing escape of thepropellant gases during and after passage of the bullet through-theescape opening ofthe recess or open chamber. r

' In the accompanying instant specificationand-in which like numberslike parts throughout the several views.-

. Fig. 1 is a vicwinside elevation with parts in section of an openchamber revolver, the view showing an open drawings which form partoffthe refer to chamber of the revolverdoaded with the new and im- Fig.3 isa; fragmentary viewin section taken along the line 3 3 of Fig. 1showingthe rotary chamber-revolved from the battery position showninFig.l to the cartridge ejecting position; b Fig. 4 is a somewhat enlargedfragmentary view in section taken along the line 4-4 of Fig. l, the viewshowing detailsof the cartridge construction;

Fig. 5 is a fragmentary isometric view of the open chamber revolverofFig. 1 showing details of the open chamber; s a t Fig. 6 is a viewinsection and to an enlarged scale of the ammunition shown intheopen-chambe'r revolver of 'Referring' now more particularly to theaccompanying drawing,-a rotary drum 1 is mounted for rotation on itscylinder axis" in 'a frame 2 by means of coaxially aligned shafts 3and 4at its respective opposite ends. The drum isrecessed longitudinally toprovide aplurality': of open chambers 5 which, as here preferablyembodied, at l-thr'e in number and are spaced at equal distancescircumferentially around the drum.

v The chambers 5 are identical and paralleltherotatiom a l axis of-thedrum'. The sidewalls 6 of each chamber 'are arcuate in shape,each'l1aving a radius of curvature the same as that of the drum. Thus,each chamber is adapted to receive within its confinesa cartridge in accordance with this invention having a configuration preciselyconforming' to that of the chamber. Moreover, each chamber extends fromone end to the other of the drum so as toprovide an escape opening 1 atoneend of thefdrum and a primenopening 8 at the oppositeendofthedrum. r1 1 As shown in Figs; 1' and 2 the drum is in battery position in whichthe topmost chamberofthe three chambers in the drum-is aligned witha'barrel 9 carriedfby the frame 2. In this position, the geometricallylongitu dinal "axis of the chamber is coaxially aligned with the Theframe 2 forms a breech for the open top of the primer opening 8 of thechamber when the latteris in battery positionL-To this end, the frameZis provided Fig. 1 spans-the charnber from end to end 'and, as shown inFig.2'spans the chamber-between the walls 6 and,

preferably, is dimensionedto overlap the wall's6 seas s em completely.to close the open top or mouth of the cham- 7 her. The cylindricalbreech surface' 11 is concentric with the rotational axis of the drum 1and is of a radius of curvature which is substantially the same as thatof the cylinder surface of the drum. Thus, as the drum is rotated, itscylinder surface and the cylindrical breech surface 11 will be insubstantially wiping engagement with each other. Moreover, as is bestseenin Fig. 4, the cartridge 12 with which the chamber 5 is loaded, is,like the chamber, of non-circular configuration externally. matchingthat of the chamber. The walls 13 of the cartridge are, as shown,arcuate in shape and of a radius oficurv'ature the same as that of thedrum 1. Thus, when the cfl t idgeis positionedin the chamber, theuppermost Wall of the cartridge for-ms a continuation of the cylindricalsurface of the drum so that the drum is. capable of rotating freely withrespect to the cylindrical breech surface 13 of the frame 2. Moreover,since each of the walls 13 ofthe cartridge are of the same curvature,the cartridge may be inserted in the chamber 5 with any one of its sidesuppermost so that indexing of the cartridge with' respect to the chamberduring the loading operation, is unnecessary.

Closure of the primer end of the chamber 5 in the battery position iseffected by a flat breech surface 14 which is'normal to the rotationalaxis of the drum 1 and is in closely spaced parallel relation to thebreech end, surface 15 of the drum. Thus, the breech-surface provides astrong and rigid supporting surface against which the primer end ofthecartridge 12 is adapted to hear when the cartridge is fired. f

, T e frame2 also serves to support a firing pin 16 and a hammer 17which latter is actuated by suitable trigger mechanism including trigger18 and hammer-actuating sha t19- The shaft 19 is reciprocably mounted inthe frame 2, being. connected at its one end to the hammer 17 by meansof a pin 20 which rides in a slot 21 in the hammer. The opposite end ofthe shaft 19 is bifurcated to receive within the yoke thereby formed,one'endof the'trigger 18 which latter is provided with an arcuate slot22 which I receives a Pin 23 so that rearward movement of the trigger onits trigger pin 24, will effect a forward movemerit of vthehammer-actuating shaft'19 and, in turn, movement of the hammer to acocked position as shown in Fig. 1. The shaft 19 carries a hammer spring'25 concentric t herewith tending to, drive the-head 26 of the hammeragainst the firing pin 16.

Means are provided for effecting rotation of the drum 1 so.assuccessively to bring the chambers 5 each to the batt ry. pos i du ino kin lcf he amm n tolock the drum in'bat't'er'y tionas' thehammerfalls.A h re. pr rably em d th r'u'm af or aX1e4 hich is iouma l d i he am i2i p o d d t s o ward endwith a cylinder earn 27 having a' number ofcammingfsurfaces 28 disposed longitudinally and circumferentiallythereof, there being one such camrning surface for each. of the chambersof the drum A cam actuating lever 29 is pivotally slidably mounted on apind30 carried by the frame 2 so as to engage the cam- 1 thing surfaces28 one at a time and to rotate the cylinder cam 27' and thus the .drum 1through a"120. angle of rotation for each full rearward movement of thetrigger 18. The lever 29 terminates at its one end in a cam actuatingsurface 31 engaging the cam surface 28' as shown in" Fig. l, andterminates at its opposite end in a slot 32 receiving the pin 23 carriedby the trigger 18.

The lever 29 is also slotted intermediate its ends as at 33, for thereceptio'nof the pivot pin 30 in order that angular movementof the leveron the pin 30 maybe accompanied by lengthwise movement of the lever on.the pins .30 and 23. Qlockwise movement of the lever .29 as yiewe'd in lis opposed by a return spring'34 carried by the frame 2 so that as thecam actuating surface 31' of the lever escapes from the cam surface 28,

a: the lever will'be: snapped back to its starting position inengagement with-the left hand end of henext succeed-I ing cam surface28. p t

Means are provided for locking the drum 1 against rotation in the cockedposition of the hammer as shown in. Fig. -l. The locking means comprisesa detentv 35 pivotally mounted ona pin 36 carried by the frame 2, thedetent being urged into locking position in a recess 3-7 in the drum 1by a spring 38 carried by the frame 2. One such recess is provided foreach of the chambers 5 in the plane of symmetry of the chamberin' thebattery position. The detent 35 includes a sear 39 whichis pivotallymounted as to 40 on the detent and is adapted to be'engaged by anactuating pin 41 of a pinion 42 which, in turn, operatively engages arack- 43 on the hammer actuating shaft 19. As will be apparent from Fig,l, with the parts in-the position there shown, the drum 1 is lockedagainst rotation by the detent 35. Further rearward movement of thetrigger 18 from the position shown will cause the cam actuating lever 29to escape from the cam surface 31 thereby releasing the hammer so thatit will strike the firing pin 16. 1 In this operation thehammer-actuating shaft 19 moves to the'rightas viewed-in Fig. 1 underthe action of the spring 25, rotating the pinion 4 2 in acounterclockwise direction so that the pinionpin 41 engages the sear 39and displaces it on its pivot pin 40. The detent will remain in lockedpositionin the recess 37. Then, at the inception of the next-rearwardmovement of the trigger, the pinion Pl1141 will engagethesear 39 torotate the detent 3-5 in a counterclockwise direction against the actionof" the spring 38 and thus free the detent from the recess 37. The drumis now free to be rotated by the cam 27 driven by the lever 29, thisrotation continuing until the next chamber is brought into batteryposition, at which time, the pinion pin 41 escapes from the sear 39permitting the spring 38 to move the detent into the related recess 37in this succeeding battery position.

- A magazine unit '46 is detachably connected to the frame 2, the unitforming a handle for the gun and its interior providing a chamber 47partitioned centrally between its side walls by a partition member 43 topro- .vide right-hand and left-hand compartments adapted each to containa verticalrow of cartridges in side ,by side relation. The magazineunit' is open at its top and is detachably connected to the frame 2-by abifurcated clamp 49 at the top of the partition member 48, the clamphavingoppositely depressed clamping flanges 50 seated in grooves 51 inthe frame 2. By this arrangement the magazine unit can be readilydetached for loading with ammunition. As will be seen from Fig. 2, theright-hand an djleft-hand. compartments 52 and 53, respectively, ofthemagazine unitare-open at the top so thatgthe topmost-roundyofjthe rowof'ammunitio'nin either compartment-isfiadapted to enter the first emptychamber of thedrum 1 which comes in opposition to the topmost round.Means are provided for forcing th'e top-. most round intothe emptychamber and as here preferably embodied eajch of the chambers isprovided with a springpressed follower as at 54 and 55 respectively.

The follower 5. for example, presses against the-bottom-- mo st round ofthe row of ammunition in the'chamber 52 thus urging.. the.topmost roundinto sliding contact with, the cylindricalsurface of the drum '1. :InFig. 3

the drum 1 is shown in-cartridge ejecting position after having beenrotated from the battery position'shown in Fig. 2. -Thus, the right-handchamber 5 is empty and, i

when the drum is further rotated the empty chamber will; be brought intoposition with the topmost round in the chamber 52; the round then beingforced into and seatedain the chamber by the action of the springpressed follower 54 at the bottom of the chamber. 'It will be, apparent'that'so long as the empty chamber is loaded with arnmunition from theright-hand compartment 52, no

- ammunition will be transferred'fromtheleft-hand cham- :ber 53 into thedrum. vI Iowever, so soon as the right, i

the arrangement of the cartridges in the magazine unit.

It will be apparent that the rotary drum 1 positioned at the open top ofthe magazine unit serves as 'a gating and conveying devicefor preventingthe escape of ammunition from the magazine unit and for picking off thetopmost round of the row of ammunition for conveyance to the batteryposition.

Means are provided for ejecting the empty cartridge case from thechamber after firing. As here preferably embodied, the drum 1 is slottedradially at the bottom "ofeach of the chambers 5 so asv to providethereat a slot 56 within which is pivotally mounted an ejecting lever 57in such fashion as to bear upon but not press against the opposinglongitudinal apices of the cartridge 12 when thelatter is positioned inthe chamber. The lever 57 extends beyond the end 15 of the drum 1 into awell 58 in the frame .2, the well 58 being generally concentric with thedrum shaft 3 but having a camming surface 59 (Fig. 3') extendinginwardly toward the drum shaft 3. The camming surface 59.is of aconfiguration suitable to depress the projecting end of the ejectinglever 57 as the magazine unit, as has been described above.

As has also been described above, the'cartridge 12 is of non-circularcontour externally and is received in the non-circular-chamber 5 of thedrum, the chamber being capped or closed in the battery position'by thecylindrical breech surface 11. It will thereforebe apparent that thecylindrical breech surface 11 and the walls 6 of the open chamber 5together form a closed chamberfor the cartridge 12 in the batteryposition. The walls of this closed chamber are substantially continuousexcept for the joints at the opposite sides of the mouth of the chamber5 where the walls 6 of the chamber abut the cylindrical breech surface11. y

Interiorly, the cartridge 12, as depicted in Fig. 4 is also ofnon-circular contour so that the expansion of gas within the cartridgeon firing will tend to cause the arcuate walls 13 of the cartridge totake a circular contour. In so doing each wall '13 is thereby firmlysupportedthroughout its whole circumferential area by either the walls 6of the open chamber 5 or the cylindrical breech surface 11 of the frame2. The cartridge walls :13 arereinforced at their intersections witheach other so that at the joints of the closed chamber formed by thedrum1 and the frame 2 in battery position, the cartridge case will besufliciently strengthenedto ensure against any possibility oflongitudinal bursting of the case at the joints under the pressureof theexpanding gases. t

Means are provided'within the cartridge case formed by the arcuate walls13 for supporting a projectile or bullet 60'of cylindrical contourWholly within the interior of the cartridge case and with its axis ofrevolution'in alignment with the axisof the bore of thebarrel 9, and forforming an obturating flange at the muzzle end of the cartridge caseadapted to seal hermetically the joint between the cartridge case andthe breech end of the gun barrel 9. To this end, a cylindricalsleeve'lil jackets the bullet 60 and terminates at its one end in anannular radially extending flange portion 62 whose outer circumferential periphery is of a configuration matching that of the interiorof the ,case formed by the cartridge Walls 13.

witha reentrant skirt portion 63, as is best shown in Fig 6; serving toextend theavailable surface area for joining the'flange portion 62togthewalls 13 of,the cartridge case.

;'A primer unit 64 is positioned at and closes'the other I end of thecartridge case 13, the unit in turn being provided with a primer 65 incoaxial alignment with the longitudinal axis of the. bullet 60. t j I Itwill be apparent from theforegoing'that the bullet sleeve 61*is inannularly spaced relation to the'walls 13 of the cartridge so that thepressure of expanding gases within the cartridge will be exerted Withinthisannular space 6 6 against the annular flangeportio n 62 which, in

battery position, abuts the breech end 67 of the barrel9 and thus iteffectively seals the joint therebetiveeniwhcn the cartridgeis fired. k

It will be understood that certain features and suh-com binations areof=utility and may be employed without referenceto other features andsub-combinations, This is contemplated by and is within thescope of myclaims. It is further, obvious that warious changes may be made indetails within the scope ofmy' claimswithout departing from the spiritof myinvention. p I I What is claimed is; p

1. A cartridge for an open chamber gun comprising a case of generallyequilateral triangular configurationinteriorly" and exteriorly and fromend to end, in parallel planes normal to the longitudinal axis of thecase, and meansfor supporting'a bulletin the interior of said case in,annularly spaced. relation thereto, said supporting means havingconnection with said case at one end thereof and forming an obturatingflange thereat. 2.. A cartridge case for an open chamber'gun, ofgenerally equilateral triangular configuration interiorly and exteriorlyand from end to end, in parallel planes normal to its longitudinal axis,and means forming an obturating flange. at one end of the casecomprising a sleeve portion in the interiorof said case in. annularlyspaced relation thereto and an annular flange portion at one end of saidsleeve portion sealingly connecting said sleeve portion to thecorresponding end of said case. p U

" 3. A cartridge case for an open chamber gun of uni form equilateraltriangular configuration, interiorly and exteriorly and fromend to end,in parallel planes normal to an axis longitudinally of said caseconnecting the geometrical centersof the respective internal triangularcrosssectional areas of the interior, a sleeve in the interior of saidcase circumferentially spacedtherefrom, and a flange seal-inglyconnecting said case at one end with the corresponding'end ofsaidsleeve. P

1 4. A. cartridge case in acoordance with claim .3 inwhichitherespective' side walls of said case are, arcuatej space-equatradiusof curvature. H 1,5."A cartridge for. an opnchamber guncomprising? case of, uniform generally equilateral triangular configuration .intei-iorlyand exten'orly. and from end toqend in parallel planesnormal to the longitudinal axis ofthe case, a cylindrical sleeveoo-axial withsaid casein the interior'of said casein .circumferentiallyspaced relation.

to the walls thereof, an obturating flange sealingly connecting theother end of the case with the corresponding end of said sleeve, abullet in said sleeve, anda combustible propellant in the interior ofsaid case.

V 6. A cartridge for an open chamber gunoomprising a case whose shape incross section and from end to end, is generally that of an equilateral.triangle, a sleeve in the interior of the-case and spaced therefrom, abullet carried by said sleeve and located wholly within the interior ofsaid case, an. obturating flange sealingly connecting the case and.sleeve atbne'endof the case, and a unit, closingtheothei-end. Y i I;:}7. Arhmunition for an open chamber. gun comprising a g ca'se ofgenerally equilateral; triangular configuration interiorlyand exteriorlyand from end toend, in parallel advantageously, this flange portion 62;may be formed: 15

planes, normal, to the longitudinal axis of; the cas an means forsupporting a projectile in the interior of said case, said supportingmeans having sealing connection with said case at one end thereof andforming an obturating flange thereat.

8. Ammunition in accordance with claim 7 in which said supporting meanscomprises a sleeve having a cy'lindrical bore for containing theprojectile, said sleeve having an obturating flange at its outer end andhaving sealing connection with said case.

9. Ammunition for an open chamber gun comprising a case of generallyequilateral triangular configuration interiorly and enteriorly and fromend to end, in parallel planes normal to the longitudinal axis of thecase, and means for supporting a projectile in the interior of the caseand for forming a gas seal with the case, the support and seal-formingmeans having gas sealing connection with the inner surface of the caseat one end thereof and providing an internal obturatting flange ofuniform wall thickness thereat.

10. Ammunition according to claim 9 wherein the case is of uniformgenerally equilateral triangular configuration and is thickened at theintersection of the case walls.

11. Ammunition according to claim 9 wherein the supporting andseal-forming means providing the obturating flange at the one end of thecase comprises a sleeve portion in the interior of the case in annularlyspaced relation thereto and having a cylindrical bore for containing theprojectile, and an annular flange portion at one end of the sleeveportion sealingly connecting the sleeve portion to the corresponding endof the case, the annular flange portion including a reentrant triangularskirt portion of uniform thickness having the gas sealing connectionwith the inner surface of the case.

12. Ammunition for an open-chamber gun, comprising an elongated hollowbody having a central cylindrical bore portion extending longitudinallyof said body, for telescopical l y receiving a projectile to bepropelled therefrom, the outer surface of said hollow body being ofgenerally equilateral triangular configuration from end to end, in crosssectional planes normal to the cylinder axis 10 of said bore portion,one side of the triangular surface being arcuate.

13. Ammunition for an open-chamber gun in accord ance with claim 12, inwhich each of the three sides of the triangular surface is arcuate andhas the same radius of curvature.

14. Ammunition for an open-chamber gun, comprising an elongated hollowbody having three side walls and, at one of its ends, an end wall, saidhollow body being of generally equilateral triangular configuration incrosssection and from end to end, said end wall lying at right angles tosaid side walls and sealingly connecting said side walls together at thesame end of each to form, a closure for said body at said end, and saidside walls each having a convex arcuatc outer surface portion whoseradius of curvature is the same for each side wall.

15. Ammunition for an open-chamber gun in accordance with ciaim 14, inwhich each said side wall has a wall thickness at its intersection witheach of the other two side walls, which is greater than its wallthickness midway between its intersection with said other two sidewalls.

16. Ammunition for an open-chamber gun in accordance with claim 14,including projectile means disposed in its entirety within the hollowinterior of said body and adjacent the end thereof opposite said endwall, said end wall having an opening for the reception of igniter meanstherein, a charge of combustible propellant in the hollow interior ofsaid body for propelling said projectile means upon ignition, andigniter means in said opening in said end wall for igniting saidpropellant charge.

References Cited in the file of this patent UNITED STATES PATENTS650,461 Haws May 29, 1900 1,470,591 Behar Oct. 16, 1923 1,659,625 CowanFeb. 21, 1.928 1,896,515 Hoffman Feb. 7, 1933 FOREIGN PATENTS 716 GreatBritain of 1881

